Stereoscopic image display technology is also known as three-dimensional image display technology or 3D (Three Dimensions) display technology, which is committed to completely reproduce the three-dimensional information of objective images and display stereoscopic images with feelings of depth. A viewer that watches a 3D image can directly recognize the distance and depth relations among objects in the 3D image, which enables the viewer to feel as if he is on the scene and enjoy intense visual impact.
The 3D display technology can be divided into visually-aided 3D display technology and naked-eye 3D display technology. The visually-aided 3D display technology achieves the 3D display effect with the aid of 3D glasses, 3D helmets or other visually-aided devices. Since the visually-aided 3D display technology is easy to realize, currently most 3D display employs the visually-aided 3D display technology. However, the visually-aided 3D display technology requires the viewer to wear visually-aided glasses or helmets, and thus causes a huge inconvenience to the viewer. The naked-eye 3D display technology enables the viewer to watch the 3D image without wearing any visually-aided devices such as visually-aided glasses or helmets, and thus is getting more and more attentions.
Stereoscopic vision is a born ability of human eyes. A person can perceive a depth of an object by information such as subtle difference and parallax etc. of the image observed by the left and right eyes, so as to identify the three-dimensional information of the object. Referring to the case that the person observes the external world with his eyes, the problem to be solved by the naked-eye 3D display technology is to separate the left-eye image and right-eye image so that the left-eye image and right-eye image are respectively observed by the left eye and right eye and the left and right eyes obtain parallax images without mutual interference. The key point here is how to assign the left eye and right eye images to the left and right eyes, respectively.
Currently, the naked-eye 3D display technology generally employs a 3D grating, and the 3D grating has a beam-splitting function so that the left-eye and right-eye images are respectively emitted to the left and right eyes to realize the 3D display effect.
The 3D grating mainly includes a slit grating and a lenticular lens grating. The slit grating has caught great attention because of its simple structure and low cost. The structure of the 3D liquid crystal display having the slit grating is shown in FIG. 1. As shown in FIG. 1, the 3D liquid crystal display mainly includes an array substrate 11, a color filter substrate 12, and a liquid crystal layer 13 sandwiched between the array substrate 11 and the color filter substrate 12. Polarizing sheets are provided on the outer surfaces of the array substrate 11 and the color filter substrate 12, and the slit grating 14 is provided on a side of the color filter substrate 12 facing to the liquid crystal layer 13. However, the 3D display with the slit grating has the following drawbacks. The slit grating generally consists of a transparent strip region and an opaque strip region, and the opaque strip region will block a portion of the light emitted from a backlight unit, resulting in low brightness of the 3D display. The lenticular lens grating is formed of transparent materials and will not block the light. However, the lenticular lens grating is of high production cost and needs to be additionally formed on the color filter substrate, resulting in a more complexity and an even higher production cost of the 3D display.